Wide track vehicle

Abstract

A wide track vehicle with improved skid steering by having a chassis (1) supported upon two independently drivable tracks (2) by side support wheels (3) engaged with each track adjacent the outer edges only. Downwardly projecting rubbing strips (11, 12, 13) are attached to the underside of the chassis (1) to engage slideably with each track only when the track is upwardly deflected by uneven terrain. The tracks (2) each rotate upon a plurality of full width direction-changing rollers attached to the chassis and each having a rolling surface which is provided with mud-cutting, helical ridges (18).

We claim: 
     
       1. A tracked vehicle having a chassis (1) supported on two independently drivable, parallel tracks (2), together extending substantially the full width of the chassis so as to cover the belly thereof, wherein the chassis (1) is supported upon a plurality of side support wheels (3) engageable with an inner face of each track adjacent the outer edge only thereof, at least one longitudinally disposed rubbing strip connected to the belly of the vehicle chassis being located inwardly of each plurality of support wheels (3) and having less downward projection than the side support wheels, thereby to be slideably engageable with the inner face of the track only when the underlying track is upwardly deflected by uneven terrain. 
     
     
       2. A tracked vehicle as claimed in claim 1 wherein the chassis (2) is provided with a parallel plurality of the said rubbing strips (11, 12, 13) located inwardly of each plurality of side support wheels (3), each strip being of progressively reduced downward projection with increased proximity to the centre line of the vehicle. 
     
     
       3. A tracked vehicle as claimed in claim 1 wherein each track (2) rotates upon a plurality of full width, track-direction-changing rollers (4, 5) each having a rolling surface (17) provided with a plurality of helical, mud cutting ridges (18) engageable with the said inner surface of the track (2). 
     
     
       4. A tracked vehicle as claimed in claim 2 wherein each track (2) rotates upon a plurality of full width, track-direction-changing rollers (4, 5) each having a rolling surface (17) provided with a plurality of helical, mud cutting ridges (18) engageable with the said inner surface of the track (2). 
     
     
       5. A tracked vehicle having a chassis supported on two independently drivable, parallel tracks, together extending substantially the full width of the chassis so as to cover the belly thereof, wherein the chassis is supported upon a plurality of side support wheels engageable with an inner face of each track adjacent the outer edge only thereof, a plurality of longitudinally disposed, laterally spaced, parallel rubbing strips being located inwardly of each plurality of support wheels and having less downward projection than the side support wheels, each strip being of progressively reduced downward projection with increased proximity to the centre line of the vehicle thereby to be slideably engageable with the inner face of the track only when the underlying track is upwardly deflected by uneven terrain. 
     
     
       6. A tracked vehicle as claimed in claim 5 wherein each track rotates upon a plurality of full width, track-direction-changing rollers each having a rolling surface provided with a plurality of helical, mud cutting ridges engageable with the said inner surfaces of the track. 
     
     
       7. A tracked vehicle having a chassis supported on two independently drivable, parallel tracks, together extending substantially the full width of the chassis so as to cover the belly thereof, wherein the chassis is supported upon a plurality of side support wheels engageable with an inner face of each track adjacent the outer edge only of each track such that the weight of the vehicle is principally carried only at the outer edge of each track in normal running on relatively even terrain and the track portions inwardly of the support wheels and extending to the inner edges of the tracks are substantially unsupported against upward movement so as to be deflected upwardly when passing over uneven terrain, at least one longitudinally disposed rubbing strip being located inwardly of each plurality of support wheels and having less downward projection than the side support wheels, thereby to be slideably engageable with the inner face of the track only when the underlying track is upwardly deflected by uneven terrain.